(REVISED ABSTRACT) Funds are requested for a Finnigan Element2 magnetic sector field high-resolution inductively coupled plasma mass spectrometer (HR-ICP/MS). The Element2 is the most sensitive analytical instrument available for high-resolution multi-elemental/isotopic identification and quantitation. The requested instrument will serve as a state-of-the-art bioanalytical core resource for a diverse network of highly productive, innovative biomedical researchers at Harvard Medical School (HMS)/Harvard School of Public Health (HSPH) who require trace/ultra-trace analytical capabilities for a wide range of biomedical, metallomic, and metalloprotein biochemistry applications. Magnetic sector field technology supercedes quadrupole-based systems and provides unequivocal mass resolution, multi-elemental/isotopic sensitivity, polyatomic interference-free detection, and high-throughput performance and is the accepted standard for high resolution multi-elemental/isotopic applications in geochemistry, material science, and the semiconductor industry. Utilization of this technology in biomedical research is just beginning and allows metallomic assays, isotopic ratio dilution/tracer experiments, clinical toxicology/biomarker epidemiology analyses that have not been previously achievable. Very few HR-ICP/MS instruments are dedicated to biomedical/metallomic research anywhere in the world and none in the US. The requested instrument will be utilized as an inter-institutional cooperative core resource located at the Brigham & Women's Hospital, Boston. The instrument will be operated by an analytical team with over two decades of experience/expertise in biomedical trace metal analysis, including ICP/MS. The facility will be dedicated to biomedical metallomic research within the HMS/HSPH system and will be available to researchers at other regional institutions. Instrument siting capitalizes on proximity to major core facilities including the Trace Metal Laboratbry (HSPH), Harvard Institute of Medicine (HMS), Harvard Center for Genetics & Genomics, Harvard Center for Neurological Diseases, the Center for Aging, Genetics and Neurodegeneration, and the Taplin Biological Mass Spectrometry Facility (HMS). The Major Users Group includes interdisciplinary teams at the forefront of research in cellular/molecular biology, metalloprotein biochemistry, physiology, environmental toxicology and epidemiology, biometal metabolism/homeostasis, ophthalmology, urology, gastroenterology, and neuropsychiatry. Acquisition of this instrument will propel cutting-edge research in Alzheimer's disease, inflammatory and neoplastic diseases, cataracts, neurodevelopment, hypertension, and environmental toxicology. The principal investigator and Advisory Committee will promote equitable instrument access and cost-effective utilization to researchers throughout the geographic region. We anticipate that this core facility resource will catalyze discovery in biomedical metallomics and accelerate establishment of a Center of Excellence at the forefront of this new field. [unreadable] [unreadable]